1. Field of the Invention
The invention relates to video-graphics controllers and in particular to a single-chip processor for the simultaneous display of color image data on two display devices having inconsistent refresh requirements, such as interlaced TV and color DSTN.
2. Background of the Invention
Portable computers (e.g., laptops, notebooks, etc.) are becoming more powerful and are currently being used for multimedia video-graphics presentations in which a color image is displayed simultaneously on a CRT monitor or color television receiver and the computer's own flat-panel color display. Or the CRT or TV is used to display a color presentation while the portable's color display is used to display an outline of the presentation for use by the presenter.
At the present time, no single-chip video-graphics controller can handle such diverse display needs because the refresh rates for the CRT/TV and the flat-panel display are not compatible. The current solution to the problem is to use two different controllers, each specialized for the particular display device it must control. Such an arrangement is both expensive and power consuming since both controllers operate all the time.
What is needed is a controller architecture which will permit the functions of the two controllers to be incorporated into a single chip and which permits a wide variety of display types to be accommodated by appropriate programming while offering the power savings inherent with a single-chip device.